While crossover appearances are not uncommon in television shows (it an easy way to promote a second show), this particular instance was unusual. Even though the two shows were produced by the same studio (Columbia), they were broadcast by different networks. Donna's show was on ABC while Dennis' show was on CBS.
Jay North and Joseph Kearns reprise their roles from the CBS series "Dennis the Menace" in this episode, which aired on ABC. This marks one of the earliest times in TV history that two scripted series on different networks cooperated on a multi-network crossover, not counting variety shows.